This invention relates to medical devices for the treatment of vascular diseases generally referred to as endoluminal prostheses. A variety of such devices are available for a broad range of treatment modalities. Examples of such devices are “vascular grafts” and “stents.” Vascular grafts are typically used to treat weakened areas of vessels known as aneurysms. Stents are typically used to prop open a narrowed or stenosed vessel.
Stents and grafts may be delivered intraluminally through a narrow incision or a puncture in the patient's skin. The device may be mounted on a delivery catheter and inserted into a corporeal lumen through the skin. The device and catheter are then advanced through the various lumens to the site to be treated. To accomplish this, stents and grafts are generally collapsible for delivery and expansible for treatment.
Vascular grafts are primarily composed of an artificial lumen which isolates the natural lumen from the flow of bodily fluids, such as blood. Grafts may incorporate attachment devices to secure the graft into the natural lumen and keep the graft expanded. Stents are typically formed of metallic wires or bars configured in a cylinder. Prior art stents for sealing a graft to corporeal lumen include narrow, sharp tails that can cause wear to the relatively soft graft. The wear is a function of the radial force of the stent, the sharpness of the stent, and the amount of relative motion between the stent and the graft.
The prior art also teaches methods of manufacturing stents from tubular shape material. Such methods require the manufacturer to remove material from radial surfaces to produce the stent pattern. Raw tubular shape material, as well as processing tubular shape material, is relatively more expensive than the cost and processing of the material in other forms.
Hence, those skilled in the art have recognized a need for providing a prosthesis which produces less wear between the prosthesis and the softer graft material. The need producing stents with non-tubular shape materials has also been recognized. The present invention fulfils these needs and others.